This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. SPECIFIC AIM 3 of CORE B Historical efforts by the CIVM to generate high-quality 129Xe MR images in animals have resulted in translation of this technology to the clinical arena. There now exists a clinical infrastructure for doing hyperpolarized 129Xe MRI in human subjects. This infrastructure uses a GE 1.5T scanner running at revision 14M5 and is currently imaging human ventilation using a multi slice gradient echo method. However, a critical aim in exploiting the most important properties of hyperpolarized 129Xe MRI is to directly image the 129Xe that enters in to the pulmonary blood stream. Such a method was first demonstrated by the CIVM in (B. Driehuys, G. P. Cofer, J. Pollaro et al., Proc. Natl. Acad. Sci. U. S. A. 103, 18278 (2006)). It is now critically important to translate this method to the clinical setting. This is a specific aim our Core 2 of our P41 grant and is generally regarded in the field as the most important remaining technical step to realizing the full clinical potential of hyperpolarized 129Xe MRI. The core step needed to image 129Xe dissolved in pulmonary blood is to implement radial imaging on the clinical scanner. Radial imaging with its ultra short echo time is the key to imaging the short T2* signal of dissolved 129Xe in pulmonary tissues. This project proposes to use the infrastructure and talents of the CIVM to establish 3D radial imaging, with multi-nuclear capability on the clinial 1.5T scanner in the department of radiation oncology where current clinical 129Xe imaging is taking place. In addition to establishing the imaging sequence, this project also seeks to establish a robust pipeline for carrying out the reconstruction of the data. It will hence draw heavily on the expertise and talents of Gary Cofer for the pulse sequences and Sally Gewalt for the reconstruction. We will likely need the help of Lucy Upchurch to manage the necessary IT infrastructure that backs the reconstruction pipeline.